Glycemic control in people with diabetes treated with cancer chemotherapy: contribution of continuous glucose monitoring

Aims The aim of our study was to assess, with Continuous Glucose Monitoring (CGM), exhaustive information on the glucose profile in people with diabetes starting chemotherapy. We also evaluated the adaptation of glucose-lowering drugs following analysis of CGM recordings. Methods Eighty-five people with diabetes starting chemotherapy were included in the ONCODIAB study. A CGM was worn for up to fourteen days in blinded mode before and after the diabetologist’s intervention to evaluate the impact of modifying the glucose-lowering drugs. Results Time spent in range was 67.2 ± 24.2%. Time below the target glucose range (TBR) (< 70 mg/dl) was 8.9% in all the study population. TBR was significantly higher in patients treated with at least one drug due to the risk of hypoglycemia compared to the others (11.5% vs. 4.4%, p = 0.009). Sixty-five patients had available sensor data for the two recordings. Forty-one patients (51.9%) saw a decrease in their antidiabetic treatment after the diabetologist’s intervention guided by the first CGM recording. We observed a significant reduction in the time spent below the target glucose range (70–55 mg/dl) between the two CGM recordings (10.3 ± 14.6% vs. 6.3 ± 9.4%, p = 0.016 and 3.8 ± 8.4% vs. 1.2 ± 2.9%, p = 0.012, respectively). Conclusions CGM use in blinded mode could be an interesting tool to reduce the risk of hypoglycemia in people with diabetes starting chemotherapy. Our findings fully support the recommendation that assessing hypoglycemia risk should be mandatory in patients with diabetes before starting chemotherapy.